<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>test</title>
    <style>
        .test {
            background-color: lightsteelblue;
            height: 100px;
            line-height: 100px;
            position: relative;
            vertical-align: middle;
        }

        .inner {
            /* position: absolute;
            top: 50%;
            -webkit-transform: translateY(-50%);
             */
        }

    </style>
</head>
<body>
    <div class="test">
       <div class="inner">hello world <br/>asdf</div>
    </div>
</body>
</html>